Washer and method of determining load weight for same

ABSTRACT

A washer and a method of determining a load weight are disclosed. The washer includes a tub which stores clothes to be washed, and a motor which rotates the tub. It further includes a microprocessor which measures an acceleration time during which the motor rotates up to a certain speed, and a deceleration time during which the motor comes from another certain speed to a full stop. Then, the microprocessor determines the load weight by using at least one of the acceleration and the deceleration times.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Application No.P2003-59805, filed on Aug. 26, 2003, which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a washer, and more particularly, to adrum washer and a method of determining a load weight in the washer.

2. Discussion of the Related Art

Generally, a washer performs a washing operation by executing washing,rinsing, and dehydrating cycles. Washers may be categorized into apulsator, an agitator, a drum type, and the like based on how thewashing cycle performs.

Referring to FIG. 1, a body 1 includes a tub 2 inside of the body 1,which is connected by a damper (not shown in FIG. 1). Dirty clothes tobe washed are placed in the tub 2, and a driving force of a motor 10 istransmitted through a belt 11, which rotates a drum 3. In the mean time,water is added through an inlet pipe 6 while a thermometer 4 (e.g.,thermistor) measures a temperature. The water is drained by a drain pump8 through a drain pipe 7, which is connected between the tub 2 and thepump 8. Finally, the water exits to the outside through a drain hose 9,attached from the pump 8 to the outside.

Utilizing the washer illustrated previously, a user opens the doorprovided (not shown in the FIG. 1) on the front side of the body 1.After inserting the dirty clothes into the tub 2, the user initiates awashing operation by selecting a washing option on the control paneldisplayed on the washer. As a controller in the washer senses a loadweight and determines an amount of water, the water is supplied with adetergent from the detergent box 5, flows through the inlet pipe 6, andreaches the inside of the tub 2.

When a level of the water in the drum 3 reaches a desired level, themotor 10 starts to rotate so that the drum 3 spins. After the washingcycle, the pump 8 is turned on to drain the supplied water from the tub2. The water flows through the drain pipe 7 and the drain hose 9, andexits to the outside. After this washing cycle, the rinsing anddehydrating cycles are executed. Finally, the washing operation iscompleted.

According to the principles of the related art, as the water issupplied, the level of the water in the drum 3 elevates. Dependent uponfabric types of the clothes, the amount of the supplied water soakedinto the clothes varies. As the controller senses the level of the watertime to time and refills the water, if needed, to compensate the loss ofthe water from soaking, a number of refilling is counted and the loadweight is determined based on the number of refilling. In other words,the more the water is refilled, the heavier is the load weight.

However, the related art's method of determining the load weight hascaused a significant problem in determining proper washing parameterssuch as time intervals of the washing, rinsing and dehydrating cycles,and a temperature of the supplied water, thus resulted in descending theperformance of washers. It is due to the fact that the amount of thewater soaked into the clothes varies dependent upon the fabric types ofthe clothes. For example, the same weight of wool and nylon will weighat two different weights by the related art's method because the wooltends to soak in more moisture.

On the other hand, according to the principles of the present invention,the method of determining the load weight before the water is suppliedto the clothes resolves the related art's problem.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a washer and a methodof determining a load weight that substantially obviates one or moreproblems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a more accurate amountof water which is supplied to a washer and more precise washingparameters such as time intervals of washing, rinsing and dehydratingcycles, and a temperature of the supplied water so that the performanceof the washer can be improved.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, amethod of determining a load weight in a washer according to the presentinvention may include measuring at least one of an acceleration timeduring which a motor rotates up to a certain speed, and a decelerationtime during which a motor comes from another certain speed to a completestop. A unit of the speeds dealt with the acceleration and thedeceleration times may be RPM (revolution per minute). It may alsoinclude determining the load weight in the washer by using at least oneof the acceleration and the deceleration times.

In another aspect of the present invention, a method of determining theload weight in the washer may include at least one of an accelerationtime during which a motor rotates up to a certain speed, and adeceleration time during which a motor comes from the certain speed to acomplete stop. A unit of the speeds dealt with the acceleration and thedeceleration times may be RPM (revolution per minute). It may alsoinclude calculating a look-up value and selecting one of a plurality ofload weight values in a look-up table, corresponding to the look-upvalue in order to determine the load weight. The look-up value may beobtained by calculating a weighted value of the acceleration and thedeceleration times.

In another aspect of the present invention, an apparatus of a washerincludes a tub which stores clothes to be washed, and a motor whichrotates the tub. According to the present invention, it also includes amicroprocessor which measures an acceleration time during which themotor rotates up to a certain speed, and a deceleration time duringwhich the motor comes from another speed to a full stop. A unit of thespeeds dealt with the acceleration and the deceleration times may be RPM(revolution per minute). Then, the microprocessor determines a loadweight by using at least one of the acceleration and the decelerationtimes.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings;

FIG. 1 illustrates the front view of an existing drum washer;

FIG. 2 illustrates a schematic block diagram for the drum washer inaccordance with the present invention;

FIG. 3 is a flow chart illustrating a method of determining a loadweight in a washer according to the present invention; and

FIG. 4 illustrates a graph showing how each of T₁ and T₂ varies in termsof the load weight in the washer.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

FIG. 2 illustrates a schematic block diagram of a drum washer inaccordance with the present invention. The drum washer includes a keyinput unit 101 which receives an user's command for a washing operation,and a microprocessor 105, which determines a load weight by using thetime, T₁, during which a motor 106 rotates up to a pre-determined speed,and T₂ during which the motor 106 comes to a full stop after the motor106 is powered off. Then, the microprocessor 105 decides washingoperation parameters such as time intervals of washing, rinsing anddehydrating cycles, and a temperature of the supplied water according tothe determined load weight.

The washer also includes a water level sensor 103 which senses a levelof water in a tub 2, and a temperature sensor 104 which adjuststemperature in the tub 2, according to the control signals from themicroprocessor 105. The washer further includes a power supply unit 102which supplies the power throughout the system, a motor driving unit 107which drives a motor 106, and a heater driving unit 109 which adjusts aheater 108, by means of receiving the control signals from themicroprocessor 105.

According to the washer with the present invention, when a userinitiates a washing operation by inputting a washing option displayed onthe control panel on the washer, the microprocessor 105 determines theload weight before the water is supplied into the tub 2. The method ofdetermining the load weight is to measure the time, T₁ and T₂; T₁ is atime during which the motor 106 rotates to a pre-determined speed. Then,the motor 106 is powered off. T₂ is a time during which the motor 106comes to a complete stop after it is powered off. A unit of the speeddealt with T₁ may be RPM (revolution per minute). Now, the load weightis determined by using the times, T₁ and T₂.

FIG. 4 illustrates a graph showing how each time of T₁ and T₂ varies interms of the load weight in the tub 2. Referring to FIG. 4, it isrecognized that T₁ initially increases and eventually settles down at acertain time as the load weight increases, whereas T₂ proportionallyincreases as the load weight increases. The load weight is determined byselecting one of a plurality of load weight values in a look-up table,corresponding to a look-up value. The look-up value is calculated byapplying T₁ and T₂ to the following equation:${{{Look}\text{-}{up\_ value}} = \frac{\left( {\left( {T_{1} \times 3} \right) + T_{2}} \right.}{2}},$where T₁ denotes a time during which the motor 106 rotates to thepre-determined speed, and T₂ denotes a time during which the motor 106comes to a complete stop after it is powered off.

FIG. 3 is a flow chart illustrating a method of determining the loadweight. Referring to FIG. 3, the microprocessor 105 determines whetherthe washer is powered on (S11). If the power is on, the microprocessor105 receives a command for a washing operation from a user (S12). Then,the microprocessor 105 signals the motor driving unit 107 to drive themotor 106 and measures the time, T₁, during which the motor 106 rotatesup to the pre-determined speed (S13). The microprocessor 105 powers offthe motor 106 when it reaches the pre-determined speed.

Subsequently, the microprocessor 105 measures the time, T₂, during whichthe motor 106 comes to a complete stop (S14), and determines the loadweight by using T₁ and T₂ (S15). The microprocessor 105 supplies theappropriate amount of the supplied water into the tub 2 dependent uponthe load weight determined in the previous step (S16). Themicroprocessor signals the water level sensor 103 to determine whetherthe appropriate amount of water is supplied (S17). If the amount ofwater satisfies the water level sensor 103, the microprocessor 105executes a washing operation (S18) and assures that the washingoperation is properly completed (S19). Accordingly, the presentinvention makes it possible that the load weight is determined beforethe step of filling the water in the washer is executed so that the moreaccurate amount of the water can be supplied to the tub 2.

Therefore, according to the principles of the present invention, themore accurate load weight can be determined regardless of fabric typesbecause it is determined before the water is soaked into the clothes. Inaddition, a performance of the washer can be improved for the moreappropriate washing parameters such as time intervals of the washing,rinsing and dehydrating cycles, and a temperature of the supplied waterare selected according to the more accurate weight load. Consequently,users can be more satisfied with the improved performance of theirwashers.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A method of determining a load weight in a washer including a motorrotating a tub containing clothes, the method comprising: measuring atleast one of a first time and a second time, wherein the first timedenotes a time during which the motor rotates up to a first speed, andthe second time denotes a time during which the motor comes from asecond speed to a full stop; and determining the load weight in thewasher by using the at least one of the first and the second measuredtimes.
 2. The method of claim 1, wherein the determining the load weightis carried out before water is supplied into the tub.
 3. The method ofclaim 1, wherein the washer is a drum type washer and the tub is a drumtype tub.
 4. The method of claim 1, wherein the first and the secondspeeds are identical.
 5. A method of determining a load weight in awasher including a motor rotating a tub containing clothes, the methodcomprising: measuring a first time during which the motor rotates up toa first speed; measuring a second time during which the motor comes fromthe first speed to a full stop; and determining the load weight in thewasher by using the first and the second measured times.
 6. The methodof claim 5, wherein the determining the load weight comprises;calculating a look-up value by using the first and the second measuredtimes; and selecting one of a plurality of load weight values in alook-up table, corresponding to the look-up value.
 7. The method ofclaim 6, wherein the plurality of the load weight values in the look-uptable is proportional to its corresponding look-up values.
 8. The methodof claim 6, wherein the calculating a look-up value comprises;calculating N*T₁, wherein N is an integer and T₁ denotes the first time;adding T₂ to N*T₁, wherein T₂ denotes the second time; and dividingN*T₁+T₂ by 2 in order to obtain a weighted average value of T₁ and T₂.9. The method of claim 8, wherein N is equal to or greater than
 2. 10.The method of claim 5, wherein the determining the load weight iscarried out before water is supplied into the tub to determine theamount of the supplied water and other washing operation parameters suchas time intervals of washing, rinsing and dehydrating cycles, and atemperature of the supplied water.
 11. The method of claim 5, whereinthe determining the load weight is carried out when a user initiates awashing operation.
 12. A washer comprising: a tub containing clothes; amotor rotating the tub; and a microprocessor measuring a first and asecond times, and determining a load weight by using at least one of thefirst and second times, wherein the first time represents a time duringwhich the motor rotates to a first speed, and the second time representsa time during which the motor comes from a second speed to a full stop.13. The method of claim 12, wherein the a microprocessor determining aload weight comprises: calculating a look-up value by look-upvalue=(N*T₁+T₂)/2, where N denotes an integer, T₁ denotes the first timeand T₂ denotes the second time; and selecting one of a plurality of loadweight values in a look-up table, corresponding to the look-up value 14.The method of claim 13, wherein N is equal to or greater than
 2. 15. Acomputer software product, comprising: A computer-readable mediumstoring program code for controlling operations of a washer, the programcode, when executed by the microprocessor, causing the microprocessor toperform: measuring a first time during which a motor rotates to a firstspeed; measuring a second time during which the motor comes from asecond speed to a full stop; calculating a look-up value in order todetermine a load weight by using the first and the second measuredtimes; and selecting one of a plurality of load weight values in alook-up table, corresponding to the look-up value, wherein the look-upvalue is calculated from (N*T₁+T₂)/2, where N is an integer and equal toor greater than 2, T₁ denotes the first time and T₂ denotes the secondtime.
 16. The software product of claim 15, the computer-readable mediumstoring program code for controlling operations of a washer comprises amemory.